A team of additional inspectors from the Coast Guard's Seattle Sector boarding team were called to the scene to administer the breath test -- and found the captain to be under the influence of alcohol, Winter said, with a blood-alcohol content level above 0.040, the federal limit for operating a vessel in U.S. waters.

The Mercury, which has a capacity to carry 1,884 passengers, was delayed in port at Pier 66 for more than an hour before departing at 6:30 p.m., under the direction of another captain.

Such incidents are rare, Coast Guard officials said.

"Certainly, we've dealt with other intoxicated boaters before," said Winter, of the Coast Guard's District 13 office. "But I can't think of any other similar incident involving the captain of a vessel this large."

The incident prompted a Coast Guard investigative team to be dispatched from the Jackson Federal Building downtown to the cruise ship. The team boarded the vessel, Winter said, and sailed with the ship to the pilot station at Port Angeles.

The cruise company's policy forbids any officer from consuming alcohol within eight hours of reporting for duty, Sheeham said, noting that Royal Caribbean's policy is twice as stringent as international maritime regulations.

"The captain's actions are totally unacceptable. He has been stripped of his command and ordered off the ship," said Dan Hanrahan, president of Celebrity Cruises, in a statement. "Any shipboard employee, from the captain down, will be dealt with as swiftly and severely."

Celebrity Cruises sails weekly during spring and summer from Seattle to Alaska from the Bell Street Pier Cruise Terminal at Pier 66, where the ship was moored during the incident.

The Coast Guard said the cruse line fully cooperated with the investigation.

Lt. Cmdr. Rick Rodriguez of the Coast Guard said the captain was being investigated for operating a commercial vessel under the influence of alcohol, which is a misdemeanor punishable by up to a year in prison.

Federal law considers someone operating a vessel legally intoxicated if his or her blood-alcohol concentration level exceeds 0.040.

"This incident should send a clear message to all mariners operating in U.S. waters that operating any vessel under the influence of drugs or alcohol is a serious threat to the safety of other mariners, the general public, and maritime commerce and transportation," Rodriguez said in a statement. "Such behavior will not be tolerated, and violations will be enforced to the fullest extent."